Water heater



March 1l, A193C). A Q KEllNlN 1,750,475

A WATER HEATER Filed April 2, 1328 QL. fari M VE :DP ffz'ed Kerm'lzPatented Mar. 11, 1930 UNITED STATES PATENT OFFICE ALFRED G. KERNIN,lOFVIVIOSINEE, WISCONSIN, ASSIGNOR T MOSINEE PAPER MILLS COMPANY, OFlllIOSINIlIEl,` WISCONSIN, A CORPORATION OF WISCONSIN WATER HEATER Thisinvention relates to a heat economy apparatus and more particularly toapparatus for utilizing the waste heat contained in -steam blown offfrom digesters in pulp makmg processes.

In' the manufacture of pulp, large volumes of steam are liberated duringthe intermittent blowing off periods occurring at the end of the cookingof each successive batch of chips. 4In sulphate pulp mills especially,the steam is of a peculiarly offensive odor and, owing to itscontamination, the steam, or condensatef therefrom, is rarely used insubsequent operations, but is either vented to the atmosphere or blowninto a jet condenser Afor discharge into the sewer.

There is little use made, therefore, of the steam for producing hotwater for pulp washing purposes on account of the inferior quality ofthe water that can be made. Furthermore, owing to the intermittentcharacter of the blowing operations, if the water used in condensing thesteam is circulated continuously, the resulting water will fluctuate tooi widely in temperature to be satisfactory for washing purposes.

Accordingto my invention, however, the waste steam is condensed in aheat economy apparatus by direct contact with constantly circulatingwater and water for washing purposes is then indirectly heated from thedirectly heated water. In this way no contamination of the water forwashing can occur.

It is therefore an object of this invention to provide a heat economyapparatus for effectively utilizing the waste heat from steam to producean uncontaminated water for washing purposes.

Other and further important objects of this invention will be apparentfrom the disclosures in the specication and the accompanymg drawings.

This invention (in a preferred form) is i1- lustrated in the drawing andhereinafter more fully described.

On the drawing:

The figure is an elevational view with parts broken away and in section,of apparatus embodying the principles of my invention.

Thereference numeral l indicates a tank, preferablycylindrical in form,with a dished bottom 2 and a dome 3 -extending from the top' thereof. -Apipe 4, in the side of the dome 3, serves for the introduction of steamwhich is mixed in the dome with water to be heated thereby.. In the pulpmill, to which my invention is particularly directed, the steam enteringthrough the pipe 4 is steam, liberated during the blowing-off of adigester. The flow of steam, therefore, through the pipe 4 isintermittent and in great volume for short periods only. Y

l An outside circulating system comprising a pump 5 connected onitsintake side to a pipe 6 leading from thebottom of said tank l and on itsdischarge side to a pipe 7 connected into the ltop of the dome 3 as at 8serves to circulate water through the tank 1. This water in circulating,mixes with and condenses steam lintroduced through the pipe 4, .therebyraising the temperature of the water to any desired point. Fresh watermay be admitted into the circulating system fromA a main line 9 throughthe piping 10 controlled by la valve 11. Although the water thusdirectly heated by the steam becomes contaminated with entrainedproducts from the digestion processes, it is yet suitable for generalheating purposes. Valve controlled connections 12 and 13 serve for thediversion of apart of the heated water for any outside heatinginstallation. f f

A barometric jet condenser 14 is connected to the tank 1 by means of apipe 15 having an upturned elbow 16 opening above the level of the waterwithin the tank 1.

The condenser 14 thus serves to take care of any excess uncondensedsteam in the tank 1. Water is fed intov the jet condenser through avalve controlled pipe 17 leading from the main pipei9. The leg of thecondenser extends into a sewer pipe or the like. A piping connection 18,having a valve 19 therein, serves as a drain from the tank 1 whenever itbecomes necessary to drain the contents of said tank. The level of thewater in the tank 1 is maintained by reference to a sight glass 20 andmay be reduced to the proper level by'draining oli through a con- 1CDdensate line 21 having a valve 22 positioned therein.

In order to utilize the heat of the steam condensed by the water in thetank l, a plurality of closed coils 23 are supported from the bottom ofsaid tank by means of supports 24. lVater for washing purposes isintroduced into said coils 23 by opening a valve 25 in a pipe 27 leadingto said coils from a source of fresh Water. The heated vwater from saidcoils 23 istaken 0E from the' upper coil through a pipe 26 leading todifusers, or, wherever the hot water is to be used for washing. Inasmuchas this Water is not brought into direct contact with the heated waterin the tank 1, it is sufficiently pure for washing purposes. By reasonof the relatively large volume of water within thetank l, thetemperature to which the water for washing purposes is heated can bemaintained practically constant. A plentiful supply of hot water is thusfurnished at practically no cost and at a considerable saving over theusual practices.

I am aware that many changes may be made and numerous details ofconstruction may be varied through a wide range Without departing fromthe principles of this invention, andI, therefore, do not purposelimiting the patent granted hereon otherwise than necessitated by theprior art.

I claimv as myA invention 1. A `heat economyapparatus for usein themanufacture of pulp, comprising a'tank having a mixing dome, meansforintroducing blow-off steam into said dome, an outside circulatingsystem for drawing water from the bottom of'said tankand introducingsaid water into the top of said dome to condense said steam and beheated thereby and closed pipe coils positioned in said-tank for heating`water circulated through said coils.

2. A heat'economy apparatus for use in Ithe manufacture ofV pulp,comprising Va tank having Va mixing dome, lmeans for introducingblow-oif 'steam into said dome, an outside circulating system fordrawingwater from the bottom ofsaid tank and introducing said water intothe'top of said dome to condense said steam and be heated thereby,closed pipe coils positioned in said tankfor heating water circulatedthrough Vsaid coils, and a barometric jet condenser associated with saidtank for condensing steam vapors remaining uncondensed in said tank.

3. A heat economy apparatus for utilizing the heat of steam produced inthe blowing of sulphate pulp digesters, comprising a tank having amixing dome, meansvfor introducing blow-olf steam into said domefanoutside circulating system for drawing water from thebottom of said tankand pumping said water into the top lof s aiddorne` to' condense saidsteam, closed coils within said-tankffor the circulation of water to beindirectly heated and valved connections in said outside circulatingsystem for diverting some of the direct heated water for heatingpurposes.

4. A water heater for use in pulp mills for utilizing the heatvalue ofthe steam and gases blown olf from 4pulp digesters, comprising a tankadapted to be partially filled with water, means for withdrawing waterfrom said tank and discharging it back into said ALFRED G. KERNIN.

